6.2 -INSPECTION EQUIPMENT:
The following equipment is currently used for all Quality Assurance Inspections:
FOWLER MAX-CAL ELECTRONIC DIGITAL CALIPERSAND DIGITRIX II MICROMETERS.
These are the primary measurements devices used and have an accuracy of 0.0001 inches or 0.001 millimeters.
They are connected via cable to either the DataMyte unit or QC-Printer described below.
DATAMYTE 953 FIXED STATION DATA COLLECTOR
This unit was selected after careful evaluation of all products currently on the market. It is the main unit for all of our data collection. It is a self contained statistical computer, allowing for immediate inspection and analysis of components at the unit itself. It is also linked to a personal computer system allowing for the transfer of all data for permanent storage and analysis.
All measurement specifications, including upper and lower limits for each part being measured are stored in the unit. If a measurement is out of spec the unit will beep and flash a red warning across the screen. Once a subgroup has been measured an x-bar and range chart or histogram will be displayed representing all of the components data currently in the units memory. This data is transferred to the desktop system for permanent storage at the end of each work week, at which time the datamyte memory is emptied for the next weeks data.
The actual and date at the moment a subgroup of 5 parts has ben measured is automatically stamped along with the data. Therefore, if the official recording of the data was delayed for some reason , this time and date may not correspond exactly to the time of production. This does not mean however that the parts were not being measured while they were running or that samples were missed. All components are being continuously measured throughout their production run and samples taken for recording purposes are kept in labeled envelopes in the QA inspection area until they are measured and recorded.
The function of this unit and its setup are controlled through the PC
Using the turbo SPC software described later in this section.
FOWLER EDP-1000 QC PRINTER
This device is used as a backup system for the DataMyte unit and will generate a printed output which can then be keyed into a computer manually to produce a report.
The unit produces small 1.5 inch wide slips of paper containing the measurement data of the part being inspected. This data consists of: the upper and lower limits, dimensions measured , number of parts measured, min and max values, range,average, standard deviation, percentage out of spec, and Cp values.
A sample of these slips are shown in figure 1 and a sample of what a typical report using this data would look like can be seen in figure 2.
TURBO SPC VA SOFTWARE
This is basically the hub of the Preventative Quality Assurance Program.
This statistical Process Control software , running on an IBM Aptiva desktop computer system is used to control the datamyte 953 collection unit and download all measured data for use in statistical anaysis and report generation.
Using this software , we are now able to analyze our measured data over both short and long termed periods of time in a simple graphical manner using control charts or statistical data reports. W e can now observe trends which allow for the determination of a dies life cycle , as well as when it would need sharpening or other maintenance. This capability allows us to stay one step ahead of the production, therefore , one step ahead of potential problems.
The control chart reports which can be generated are listed as follows:
Examples of these charts can be seen in Figures 3 through 12 in the Appendix.
From these reports , any required quality assurance information can be easily accessed and analyzed.
The combination of this software and our skilled staff keeps our machines and dies under a constant state of preventative maintenance, allowing for faster and smoother production runs with a reduction in defective production.